Chris Serino, the lead homicide detective on the case, recommended charging Zimmerman the night the neighborhood watch volunteer shot and killed Martin, an unarmed teenager, in a gated community in Sanford, Fla., ABC reported Tuesday, citing sources it did not name. The network said Serino was instructed not to charge Zimmerman after the office of Brevard and Seminole county prosecutor Norman Wolfinger concluded there was insufficient evidence to prosecute the case.

Wolfinger's office said it had no comment on the report.

Zimmerman's attorney told ABC News his client was questioned for a few hours at a police station following the Feb. 26 shooting.

Martin's parents, Tracy Martin and Sybrina Fulton, spoke Tuesday in Washington at a meeting of Democratic members of the House Judiciary Committee, billed as a briefing on racial profiling and hate crimes, The Miami Herald reported.

In brief remarks, Tracy Martin said the family "will continue to fight for justice" for Trayvon Martin and Fulton expressed thanks for support the family has been receiving.

"As I've said before and I'll say again, Trayvon is our son, but Trayvon is your son," she said.

Rep. John Conyers, D-Mich., conducted the session, in which no Republicans participated, the Herald said.

"Today is not to examine the specific facts of the case," Conyers said. "That will be left to the Department of Justice and the state investigation that is under way. Our job is to understand the legislative and legal concepts that exist to consider what can be done to prevent similar tragedies from happening again."

Sanford has a duty to ensure Zimmerman is arrested, the Rev. Jesse Jackson said Monday.

"The whole world is watching Sanford," the civil rights activist said as he appeared with other civil rights leaders and Martin's parents at a City Commission meeting that was moved to the Sanford Civic Center from City Hall because of the large number of attendees.

About 500 people sat on folding chairs inside and hundreds more stood outside watching on a jumbo screen, many wearing T-shirts saying, "Do I Look Suspicious?" or "My Hoodie Does Not Mean I'm a Criminal," The New York Times reported.

"The whole world is watching Florida today," Jackson said.

The Rev. Al Sharpton -- a civil rights activist and MSNBC political commentator -- delivered a petition he said had 2 million signatures demanding the arrest of Zimmerman.

Zimmerman, 28, who is white, admitted shooting Martin, who is black, but said the 17-year-old had punched him and then repeatedly slammed his head into the sidewalk in the moments leading up to the shooting, police told the Orlando Sentinel, giving the most thorough details yet of Zimmerman's account.

Sharpton told Sanford leaders the city was poised to be saddled with a reputation for trampling the civil rights of black people if it did not take action.

"You are risking going down as the Birmingham and Selma of the 21st century," Sharpton said, referring to Alabama cities that were centers of racism during the 1960s civil rights era.

National Urban League President Marc Morial called not just for Zimmerman's arrest but also for the repeal of Florida's "stand your ground" law and for the city to clean up its police department, the Sentinel said.

The law lets people use deadly force if they think they are being threatened with serious harm or death.

The commission took no action during its Monday night meeting.

Mayor Jeff Triplett said commissioners would meet again in two weeks to allow for more public comment.

"We are in the pursuit of truth and justice," Triplett told the crowd.

Zimmerman told Sanford officers Martin punched him, knocked him to the ground and banged his head on the pavement as Zimmerman cried out for help, Sanford police told the Sentinel.

Martin's family contradicted Zimmerman's account of the moments before the shooting, saying it was Martin, not Zimmerman, whose voice is heard crying out for help on 911 tapes.

In the 911 calls released, Zimmerman is heard deciding, against a police dispatcher's advice, to follow Martin, who he said was "up to no good."

At a news conference earlier Monday, the Martin family, their lawyer and supporters said police were attempting to demonize Martin by leaking Zimmerman's account to the media.

"They have killed my son," Fulton said tearfully. "And now they are trying to kill his reputation."

Zimmerman chose to pursue Martin, who was unarmed and walking home, despite a police dispatcher's advice to stay in his car, they said.

"Zimmerman is alive and can say whatever he wants," Sharpton told the news conference, which was also attended by Jackson. "And Trayvon is dead and can't defend himself."

It was reported Martin had been suspended from his Miami high school more than once, the last time after school officials found in his book bag a plastic bag with traces of marijuana residue inside.

"What he was suspended for has no bearing on what happened on Feb. 26," said Benjamin Crump, a lawyer representing the Martin family. "He didn't do anything violent or criminal."

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